PayEx module sending the wrong order total

Hi guys.

I'm having a strange issue and I've been trying to fix it for a while now, without any luck.

I have a cart with Zone Rates as the default shipping method. The calculations are fine and the correct price is in the order total.

But when the order total is sent to the Payment site (Payex, a swedish version of Authorize.net) the shipping has changed to a lower price (the lowest price in the zone table.) The order total is however still correct as you can tell by the screen shot.

Any ideas on how to correct this are greatly appreciated.

Regards,
Peter Iwanek

Apparently the code handling the shipping, in the Payex module is this:

// Send shipping cost to PayEx
	$orderRef = (string) $response->orderRef;
	$itemNumber = (string) $i+1;
	$itemDescription1 = $order->info['shipping_method'];
	$itemDescription2 = "";
	$itemDescription3 = "";
	$itemDescription4 = "";
	$itemDescription5 = "";
	$quantity = 1;

I spoke to the Payex representative and he told me Payex does not support multiple weights (it can only handle a fixed weight, apparently). Which makes the whole thing a bit useless for us, since we will be selling books and 20 books cost more to ship than 1, obviously.